Can medical education, at any level (undergraduate, graduate, or continuing), be evidence-based? Regardless of the field of research, whether medical education or clinical outcomes, the most compelling form of evidence comes from large, randomized clinical trials (RCTs) or large, prospective cohort studies. When it comes to high-stakes decisions about interventions that will involve large populations, we expect rigorous evidence to guide decision-making. Why would we have different expectations regarding the level of evidence for medical education research than we do for clinical research? When the costs of medical care burden for the nation are so high, will we forgo an investment in educational research, and rely on regulation as our only strategy for containing cost? What would it take to show that medical education does ultimately influence patient-centered outcomes?